Fluid engine or meter



(ModeL) J. A. TILDEN.

FLUID ENGINE ORYMETBR. No. 248,679. Patented Oct. 25,1881.

Jay 2 N. PETERS. Plumb-Lithographer. WasMnglon. 0. c.

NITED STATES PATENT UFFICE.

JAMES A. TILDEN, ()F HYDE PARK, ASSIGNOR TO FRANCIS G. I-IERSEY, ()FBOSTON, MASSACHUSETTS.

FLUID ENGINE OR METER.

SPECIFICATION forming part of Letters Patent No. 248,679, dated October25, 1881.

Application filed January 31, 1881. (Model) To all 'whom it mayconcern.-

Be it known that I, JAMES A. TILDEN, of Hyde Park, Norfolk county, andState of Massachusetts, have invented Improvements in Fluid Engines orMeters, of which the following description, in connection with theaccompanying drawings, is a specification.

Myinvention relates toa water-engine,which is also capable of being usedas a fluid-meter, and has for its object to produce an engine operatedwithout valves or valve-gearing, and at the same time of simple andcheap construction.

The engine consists, essentially, of a cylinderin which the main pistontravels back and forth under the pressure of the water or other fluidentering the said cylinder, thus allowing a determined quantity of waterto pass through the apparatus at each stroke, it being expelled orexhausted from the space in the cylinder toward which the piston ismoved. The piston itself is made as a cylinder and contains a-secondarypiston, the two pistons and cylinder being provided with suitable portsto control the flow of the water through the apparatus and theconsequent movement of the two pistons. When the secondary piston makesits stroke in the main piston the fluid in the said main piston isexhausted, so that the total amount of fluid passing through theapparatus at each stroke, and measured thereby, consists of theexhaustot' the main piston and the cylinder added together. Theadmission of fluid to the main cylinder on one side of the main pistonand its exhaust on the other side thereof is controlled by the secondarypiston, and the admission and exhaust 0t fluid to and from the mainpiston to operate the secondary piston is controlled by the main piston,the exhaust-port of the secondary piston being opened by the main pistonwhen the said-main piston has arrived at the end of its stroke, by whichmovement the entrance of the-fluid to operate the secondary piston isalso allowed. By this arrangement the main piston completes its strokein one direction, thesecondary piston remaining in the same relativeposition therein, after which the seeon'dary piston makes its stroke, atthevend of ton to allow the liquid which impelled it in its last stroketo cseape,and at the same time admits the liquid to the cylinder on theother side of the main piston to cause it to make its return-stroke, atthe end of which the secondary piston mak its stroke in the reversedirection to that last described, and the operation goes on conti l1 l1y- The se onda y piston will be spoken of as stationary wh it; hascompleted its stroke in the mai piston nd remains stationary relative,to th id in piston, although the lattel, of course, is rrying thefOIDlGI' Wit-ll it in making its stroke in the cylinder. By their mutualcont l f e another each piston remains stationary while the other ismaking its stroke, since it is only when one has arrived at the extremeend of its stroke that it brings the proper ports in o nection t0 causethe other piston to make its SllrOke.

In the description the ports and passages leading the fluid to and fromthe main cylinder to operate the main piston will be distinguished bythe word main from those admitting and withdrawing the fluid to and fromthe main piston to operate the secondary piston, which will be calledsecondary.

The main inlet-passage for the fluid is at the side of the maincylinder, midway ofits length, and the main piston is provided with aninletpassage midway ot'its length, on the same side as the said inlet tothe cylinder, while the secondary pistou has a tubular passage extendingacross from side to side midway of its length, its direction being thesame as that of the two passages last described.

The pistons are of such length relative to the length of theirrespective strokes that the passages last described will never be whollydisconnected, and together form themain inlet passage through which thefluid enters, to be afterward directed to one or the other end of themain cylinder, according to theposition of the secondary piston. Thetubular passage in the secondary piston, at its end opposite to theinlet-passage of the main piston, will be brought at the end of itsstrokes into connection with one or the other of two ports in the mainpiston leading into the-main cylinder at each end ports actingalternately forinduction and eduction, like the ports of an ordinarysteamengine cylinder.

The secondary piston, which is made as a hollow drum, has two mainexhaust-ports leading to its interior, and so located that when itstubular passage is in connection with one of the ports of the mainpiston, as last described, for the induction of fluid to one end of thecylinder, one of the said main exhaust-ports leading to the interior ofthe secondary piston coincides with the other port of the main pistonfor the eduction of fluid from the other end of the main cylinder intothe interior of the secondary piston, whence it flows out of theapparatus by the exhaust-passages through the side of the secondary andmain pistons, so arranged as to remain connected during the entirestroke of the main piston, just as theinletpassages and tubular passageof the secondary piston remain always in connection, as previouslydescribed.

The main piston is provided with two sec ondary inlet-ports on the sameside as the main inlet-passage, previously described, and so arrangedthat one is brought into connection with the inlet to the main cylinderatthe end of the stroke of the main piston, thus admitting the waterinto the main piston on one side of the secondary piston to cause thelatter to make its stroke. The main piston is also provided with twosecondary exhaust-ports properly located to be brought into coincidencewith secondary exhaust-passages through the side of the main cylinderonly at the end of the stroke of the main piston.

The secondary exhaust-passage of the main cylinder and the mainexhaust-passages lead to an exhaustchamber from which the fluid may beled by a suitable pipe, and the fluid will apparently flow uniformlytherethrough, it entering first the main cylinder on one side of themain piston and passingout at the other, after which it enters the mainpiston at one side, and passes out therefrom at the other side of thesecondary piston.

The fluid may, if desired, pass through the apparatus in the oppositedirection, in which case what are described as inletpassages will becomeoutlet-passages, and the reverse.

Figure 1 is a transverse section on line 9 y, Fig. 2, of an apparatusconstructed in accordance with my invention; Fig. 2, a longitudinalsection thereof on line as 00, Fig. 1; Fig. 3, a par tial longitudinalsection on line 2, Fig. 1, showing the operation of the exhaust of thesecondary piston; Figs. 4, 5, 6, side elevations of the secondary andmain pistons and cylinder, respectively, in a position invertedrelatively to that shown in Fig. 2.

The main cylinder at is provided with an inlet-passage, b, at one side,midway between its ends, and with an exhaust chamber, c, andexhaust-passage, d, leading therefrom,also placed midway between itsends.

The main piston 0 (shown as of alength considerably more than half ofthe interior of the cylinder) is provided with a main inlet'passage, f,on the same side thereof as the inlet-passage b, the two passages bfbeing ot'such width relative to the length of the stroke that they arenever wholly disconnected, as will be seen from Fig. 2, where the mainpiston is shown at the extreme end of its stroke.

The secondary piston g, fitted within the main piston e, is made hollow,and provided with a tubular passage, h,extending diametrically across itin the proper direction to meet the inlet-passage f of the main piston,and is of such width relative to the said passage that it is neverwholly disconnected therefrom, so that the fluid entering the maincylinder at I) will always have a free passage to the opposite end ofthe tubular passage I). The pistons are prevented from turning on theiraxes to bring their ports out of proper position by suitable guides, 2.(See Fig. 1.)

The main piston c is provided on the opposite side to theinlet-passagefwith two ports, H, leading from the inside of the said piston to themain cylinder, at each end thereof, the opening within the piston beingso located that the secondary piston never passes wholly beyond them inmaking its stroke, and at the end of each stroke brings the tubularpassage h into connection with one of the said ports t' i.

The secondary piston g is provided with two main exhaust-ports, k It, soplaced that when at the end of its stroke the tubular passage h isconnected with one of the ports, as t, of the main cylinder, the otherport, i, thereof will be in connection with the correspondingexhaust-port leading into the secondary cylinder, so that as the fluid,in entering, passes through the passages 11,], h, andiinto the cylindera on one side of the main piston 13 the fluid in the cylinder on theother side of the main piston will have a passage through the ports 71kinto the secondary cylinder g, whence it will pass to theexhaust-chamber c of the cylinder by the following passages. (Best seenin Figs. 1, 4, 5, 6.) I

The secondary piston g has an opening, l, in its side of such width thatduring its entire stroke it remains in connection with the correspondingpassage at through the side of the main piston, the outer portions ofthe said passage 122. being extended, as shown at m, Fig. 5, so that itremains in connection with the port a through the side of the maincylinder during the entire stroke of the said main piston, and there isalways a free exhaust-pas sage from the space in the secondary pistonaround its tubular passage to the outside of thecylinder,just as thereis a free inlet for the fluid through the passages I) mf to the end ofthe tubular passage h.

It will thus be seen that the ports 6 i of the main piston e arealternately inlet and exhaust ports, being controlled by the secondarypiston g, which acts as a valve therefor, and while at one end of thesaid main piston, as shown in Fig. 2, admits the fluid to one sidethereof through the passage i, and allows it to pass out from the otherside thereof through the passages t" It l m a. After the main piston hascompleted its stroke in one direction, as is shown in Fig. 2, thesecondary piston is operated to change the connection of the ports t' t"and cause the main piston to move in the opposite direction, as follows:

- The main piston e is provided with two secondary inlet-passages, 0 0,on the same side with the main inlet-passage f, and so placed that theyare brought into connection with the inlet 1) of the cylinder to, one atthe end of each stroke of the said main piston, the said passagesleadingto the space within the main piston at each side of the secondarypiston, respectively. The main piston is also provided with secondaryexhaust-ports p 10, (see Fig. 3,) leading from the ends of the insidespace ofthe said piston e to the outside, Where the openings are nearthe middle thereof and come against the inner surface of the cylinder a,which is provided with secondary exhaust-ports r r, so located as tocoincide with the outer openings of the ports pp, respectively, onlywhen the main piston has arrived at the end of each stroke. Theexhaust-passage p from one end of the main piston e is thus brought intoconnection with the corresponding exhaust-port r to give a freeeductiou-passage on one side of the secondary piston at the same timethat the secondary inlet-port 0 is brought into connection with theinlet-passage b to admit the water to the other end of the main pistonto act upon the secondary piston.

The operation is as follows: The parts are shown in Fig. 2 in theposition assumed when the main piston has just completed a stroke, thefluid having entered through the passages I), f, h, and i to one end ofthe cylinder at and passed out from the other end thereof through thepassages i, l, m, and a. At this time the secondary inlet port 0 of themain piston has been brought into'eonnection with the inlet-passage b ofthe cylinder a, admitting the fluid to one end of the said piston tooperate on the corresponding end of the secondary piston therein, whilethe secondary exhaust-port p is brought into connection with thesecondary exhaust-port 1" through the side of the main cylinder topermit the fluid to pass from the main piston at the other side of thesecondary piston to allow the secondary piston to make its stroke. Atthe end of this stroke of the secondary piston 9 its tubular passage it(without being at any moment disconnected from thepassage f) is broughtin to connection with the port t" of the main piston, thus permittingthe fluid to enter from the passage 11 through the said port t" the endof the cylinder which hasjust been exhausted, and at the same time theexhaust-port k of the secondary piston is brought into connection withthe port i of the main piston, allowing the water or fluid to pass fromthe full end of the cylinder through the said ports 1. it into thesecondary piston, and thence out through the main exhaust-ports l m n,as previously described. The main piston will thus be caused to make itsreturn-stroke while the secondary piston is carried with it, but withoutmovement relative to the main piston, until at the end ofthe stroke ofthe main piston the secondary inletport 0 thereof is brought intoconnection with the inlet 1) and the secondary exhaust-port p with thecorresponding port 1" through the side of the cylinder 61, to thus causethe secondary piston to make its stroke while the main piston remainsstationary, and the operation thus continues, each piston controllingthe movement of the other, and each permitting the other to move onlywhen it has itself completed its movement in either direction.

It will be seen that in an engine constructed in this manner the onlyfitting required may be accomplished by boring and turning, thusenabling it to be very cheaply constructed, and at the same time themovements are very posi tive and certain.

The engine will operate equally well if the fluid enters at d and passesout at b.

A piston-rod, t, is shown connected with the main piston e, which may beemployed to impart the power if the apparatus be used as an engine, orto actuate recording or registering mechanism if it be employed as ameter.

It is obvious that various modifications in the construction andarrangement of the parts might be made without departingfromtheprinciple of my invention. As, for example, if the apparatus were tobe used only as an engine, the secondary inlet-ports o 0 leading intothe main piston might also serve as the exhaustports, the passages r 1being placed at either side of the main-cylinder inlet 1).

The piston-rod t may pass through a stuffingbox or an equivalent in themain piston e at 3, Fig. 2, and be connected with the secondary pistong, as shown in dotted lines, so as to get the entire stroke of bothpistons. Otherchanges might be made, according to the purpose for whichthe apparatus was to be employed,these being enumerated merely toindicate. that the invention is not restricted to the precise formshown.

By a slight modification in the position of the ports the expansiveforce of a gas might be utilized.

I claim 1. The main cylinder and its inlet-passage, and the main pistonprovided with a main inlet-passage of proper width to remain inconnection with the cylinder inlet-passage during the entire stroke ofthe main piston, and with two ports leading to the main cylinder ateither end of the said main piston, combined with a secondary pistonprovided with a tubular pas with the main inlet-passage,andto beconnected ICO 4 p 24mm with one or the other of the ports of the mainpiston, according to its position therein, substantially as described.

2. The main piston provided with ports leading to either end of the maincylinder, com bined with the secondary piston provided with a tubularpassage and with main exhaust-ports arranged as described, whereby, whenthe tubular passage is in connection with one of the main piston-ports,the other port will be in connection with one of the main exhaust-portsof the secondary piston, substantially as de scribed.

3. The cylinder provided with an inlet and main exhaust-passage, and themain piston therein provided with a main inlet-passage and two mainports leading to either end ofthe said cylinder, and a mainexhaust-passage, m m, adapted to remain always in connection with theexhaust-passage of the cylinder, combined with the secondary piston andtubular and exhaust passages therein, to be alternately connected withthe main piston-ports and the main exhaust-port 1, leading from itsinterior and adapted to remain always in connection with the mainexhaust-port m of the main piston, substantially as and for the purposedescribed.

4. The cylinder provided with an inlet-passage and two secondaryexhaust-passages, combined with the main piston therein and thesecondary piston in the said main piston, the main piston bein gprovided with secondaryinlet and exhaust ports, arranged, as described,to bring the inlet-port leading to one end of the main piston intoconnection with theinlet-passage of the cylinder at the same time thatthe exhaustport leading from the other end of the piston is brought intoconnection with one of the exhaust-passages leading from the maincylinder, substantially as described.

In testimony whereofI have signed my name to this specification in thepresence of two subscribing witnesses.

JAMES A. TILDEN.

Witnesses:

J 0s. 1. LLVERMORE, W. H. SIGSTON.

